ARLINGTON (AP) – Power supplier NRG Energy Inc. says it plans to install a network of 70 electric vehicle charging stations in the Dallas-Fort Worth metro area and another 50 in the Houston area by the end of next year.

The company said in a statement Friday that half of the privately funded charging stations should be in place by Labor Day. NRG planned to unveil the first of the charging stations later in the day at a Walgreen’s Drug Store in Dallas.

NRG also plans to install stations along the Interstate 45 corridor in Texas next year.

The first “Freedom Station” recharger will have a 480-volt direct current fast charger that can add 30 miles of range to an electric car in as little as 10 minutes, and a 240-volt charger that can add up to 25 miles in an hour, the company said in a statement. Freedom Stations will be available 24 hours a day and include a tower with a camera that gives users access to customer service.

The network also will include “Convenience Stations” that have 240-volt chargers that will be available during the host retail business’ operating hours, NRG said.

NRG said it will charge users a flat monthly fee for charging plans. The company’s complete plan costs $89 per month and covers the home charger, unlimited access to the charging network for free, and the cost of electricity to charge the car at home during off-peak hours. It also will offer a 240-volt home charger for $49 per month.

“Inaugurating the first Freedom Station in the Dallas-Fort Worth metroplex is a critical first step toward making electric vehicles the smart and convenient choice for Texans who want to reduce their cost of driving while contributing to cleaner air and America’s energy independence,” NRG President and CEO David Crane said in a statement.

Crane said the company was taking a page from Southwest Airlines when it started 40 years ago linking the major metro areas in Texas. Eventually electric car drivers will be able to use the system to drive through the region with confidence that they won’t run out of electricity, the company said.

Princeton, N.J.-based NRG Energy owns and develops power plants to sell electricity in the wholesale market.

Nissan Motor Co. and General Motors Co. recently have rolled out rechargeable battery-powered cars in the U.S., with several other automakers scheduled to bring out models this year. Through the end of March, GM sold 1,210 Chevrolet Volts, while Nissan sold 452 Leaf electric cars.

Nissan said the Leaf can go up to 100 miles on a single charge, and it takes eight hours to fully recharge the car with a 240-volt circuit. The Volt can only go about 40 miles on battery power, but it has a small gas motor on board that can keep the car going when the battery runs out. With its smaller battery pack, it can be recharged in five hours or less at 240 volts. A standard home outlet has 120 volts.